Internal combustion engine



y 2, 1933- I A. H. KING ET AL 1,907,351

INTERNAL COMBUST ION ENGINE Original Filed June 5, 1928 Patented May 2,1933 icE i ALEXANDER KING AND EAELE A. RYDER, OF wnsr HARTFORD,CONNECTICUT, AS- SIGNOR-S TO THE PRATT & WHITNEY AIRCRAFT COMIPANY, OFHARTFORD, GON- NECTIGUT INTERNAL COMBUSTION ENG-ENE Original applicationfiled June 5, 1928, Serial No. 283,081. Patent No. 1,338,408, datedDecember 29, 1931.

Divided this application filed August 81, 192*.

This invention relates in general to internal combustion engines and ismore particularly concerned with thermostatic controls governing theoperation of the same between certain ranges of combustion cylindertemperatures. This invention is a division from our original applicationSerial N umber 283,- 6-81, filed June a, 1828, patented Dec. 29, 1931No. 1,838308 and is especially directed to such thermostatic devices asapplicable to spark adjustment control, throttle control and mixturecontrol.

Internal combustion engines have a tendency to overheat under conditionsof excess load, incorrect carburetion due to the use of low grade fuelsor improper adjustment of fuel proportions, incorrect spark timing andother adverse conditions. Such conditions frequently cause detonation,which in turn causes further overheatin poor lubrication, loss inhorsepower output and the final seizing of the pistons within theircylinders and the destruction of the engine.

It is Well recognized that failure of anengine due to overheating is dueto excessive temperature of the cylinder head or cylinder walls, andthis excessive temperature may be caused either by high combustiontemperature, deficiency or" the cooling system, or a condition such asdetonation, which causes a disproportionate part of the heat ofcombustion to he transferred to the cylinder walls.

he prior artcontains eiiorts to regulate engine temperatures oy controlof the cooling means, as, for example, thermostatic control of thecooling water circulation. Such means are eiiective to maintain acertain minimum temperature which may be desirable for operation, butare powerless to limit the maximum temperature of the combustion chamberor cylinder whenever the conditions of operation cause the evolution andtransfer to the cylinder walls of more leat than the cooling system iscapable of absorbing.

In order to remove the danger which might other ise arise from excessloads, poor fuel selection, improper sparl' timing, deficiency of thecoolin system or other causes of overheating, it is the purpose of thisinvention Serial No. 389,785.

to provide a means, goverened by cylinder temperature, for controllingthe amount of heat supplied to the cylinder walls. In general anycontrol is effective which operates to reduce the pressure and/ ortemperature of combustion; or to prevent detonation if conditions likelyto cause detonation are present. iYz-inbustion temperature and efiectivecomust-ion pressure may be lowered, and detonation, it any, may bereduced by partially closing the throttle, retarding the spark,enriching the fuel mixture, or by various com binations of the movementsof these controls. It is, therefore, an object of this invention toprovide a thermostatic means for automatically controlling the movement,within certain limits, of any or all of these three con trols. I

It is the prime object of this invention to provide a thermostat inthermal commu nication with a multi-cylindered engine, and electricalmeans for translating the movements of the thermostat into positiveactuation of the engine operating controls in the manner required toreduce efiective combustion pressure.

It is a further object of our invention to so adapt this electricalmeans to the particular uses of a multi-cylindered'radial engine,providing a thermostat for each cylinder and so arranging our electricalmeans that it will be actuated by the thermostat of that cylinder havingthe highest temperature tooper:

ate the engine control, resilient means being provided to return theparts to their normal posit-ions when the temperature is decreased.Other objects ofour invention will appear in the following specificationand claims and will be disclosed in the accompanying drawing, in whichThe figure is an end elevation of our device as incorporated with amulti-cylindered radial internal combustion engine, the device beingshown diagrammatically in part. In this structure each of the cylinders3 of an internal combustion engine is provided with a thermostat fixedthereto adjacent the head portion 40 thereof. The thermostat 1v isreferabl thou h not necessaril comprised of two strips of metal ofunequal coeiiicients of expansion and is attached at one end to thecylinder. Each of these thermostats is provided with an electricterminal 34 and its free end is adapted to be movable into contact witha contact member 35. These contacts form the terminals of an electricalcircuit which includes the leads 36, the battery, or other source ofelectrical energy, 37, and the solenoid 38. The armature of the solenoidis a rod 39 which passes through a guide ll secured to the crankcase ofthe engine.

A tension spring 40 is concentrically mounted on said rod having one endsecured to the guide ll and the other to an adjustable set screw 42,also concentric of the rod. Movement of the rod into the armature isresisted by the tension of this spring. The rod, at its lower end isconnected to one or more of the engine operating controls, not shown. Itwill be noted that the thermostats are connected with the solenoid andsource of electrical energy in parallel with the result that any one ofthe same may operate the said controls.

From the foregoing our device will be seen to operate as follows:

The free ends of the thermostats are so positioned that, when thethermostat is curved, under increasing cylinder temperatures, thethermostats will engage the contacts 35 at that degree of cylindertemperature considered excessive. \Vhen contact is made by any one ofthese thermostats with its contact 34, the solenoid will be energizedand will draw the rod 39 inwardly against the action of spring 40 toretard the spark, enrich the mixture, or partially close the throttle asthe case may be.

Having thus described our invention what we claim is- 1. In combinationwith a multi-cylindered internal combustion engine having an engineoperating control, a separate thermostat for each cylinder and mountedin thermal communication therewith, an electrically operated meansoperatively connecting said thermostats and said engine control toactuate the latter when the temperature or" any of said cylindersreaches a predetermined degree.

2. In combination with a multi-cylindered internal combustion enginehaving an engine operating control, a separate thermostat for eachcylinder and mounted in thermal communication therewith, an electricallyoperated means operatively connecting said thermostats and said enginecontrol to actuate the latter when the temperature of any of saidcylinders reaches a predetermined degree, said means being adapted topermit of normal temperature increases without afiecting said control.

3. In combination with a multi-cylindered internal combustion enginehaving an engine operating control, a separate thermostat for eachcylinder and mounted in thermal communication therewith, andelectrically operated means operatively connecting said thermostats andsaid engine control to actuate the latter when the temperature of any ofsaid cylinders reaches a predetermined degree, and resiliently yieldablemeans opposing the action of said electrically operated means.

4. In combination with a multi-cylindered internal combustion enginehaving an engine operating control, a separate thermostat for eachcylinder and mounted in thermal communication therewith, an electricallyoperated means operatively connecting said thermostat-s and said enginecontrol to actuate the latter when the temperature of any of saidcylinders reaches a predetermined degree, said means being adapted topermit of normal temperature increases Without affecting said control,and resiliently yieldable means opposing the action of said electricallyoperated means.

5. In combination with a multi-cylindered internal combustion enginehaving an engine operating control, a separate thermostat for eachcylinder and mounted in thermal communication therewith, an electricallyoperated means operatively connecting said thermostats and said enginecontrol to actuate the latter when the temperature of any of saidcylinders reaches a. predetermined degree, and resiliently yieldablemeans opposing the action of said electrically operated means,

said means being adjustable to vary the eiiective force of saidyieldable means.

6. In combination with a multi-cylindered internal combustion enginehaving an engine operating control, a separate thermostat for eachcylinder and mounted in thermal communication therewith, an electricallyoperated means operatively connecting said thermostats and said enginecontrol to actuate the latter when the temperature of any of saidcylinders reaches a predetermined degree, said means being adapted topermit of normal temperature increases without affecting said control,and resiliently yieldable means opposing the action of said electricallyoperated means, said means being adjustable to vary the effective forceof said yieldable means.

In testimony whereof we have aiiixed our signatures.

EARLE A. RYDER. ALEXANDER H. KING.

